[TRNSYS-users] solar time X local time

Michaël Kummert kummert at engr.wisc.edu
Wed Feb 2 07:32:33 PST 2005


> I am using hourly weather data generated by the Meteonorm program. As 
> far as I know, this data is given at intervals of SOLAR TIME.
> (Can anybody in this list confirm this information ?)
> If I use this Meteonorm data file, obviously the Type 56 outputs will 
> also be at intervals of Solar Time. But the schedules in Prebid are 
> defined using the LOCAL TIME. I also need the simulation results in 

I believe that Meteonorm uses the time reference specified by the file 
format you select when exporting data (importing data into Meteonorm is 
another problem). E.g. if you export to TMY2 files (which is the 
recommended way in TRNSYS 16), the file will be created in local 
standard time. I am not sure about older versions of Meteonorm and 
different file formats, but this is the case for Meteonorm V5.0 and TMY2 
export format.

As always, it is easy to check which time reference is used in a data 
file by plotting the global solar radiation from the file versus the 
extraterrestrial horizontal radiation from Type 16 or Type 109. Just by 
looking at both curves, you can easily spot any time shift. You can 
configure Type 16 so it assumes the data is in solar time or not and 
compare both results.

I hope this helps,

Michaël Kummert


Michaël Kummert

Solar Energy Laboratory - University of Wisconsin-Madison
1303 Engr Res Bldg, 1500 Engineering Drive
Madison, WI 53706

Tel: +1 (608) 263-1589
Fax: +1 (608) 262-8464
E-mail: kummert at engr.wisc.edu

SEL Web Site: http://sel.me.wisc.edu
TRNSYS Web Site: http://sel.me.wisc.edu/trnsys

More information about the TRNSYS-users mailing list